ready/paymentwall: 핑백에 국가 코드 설정 설명 추가

src/content/docs/en/ready/2-pg/payment-gateway-settings/undefined-1.mdx

@@ -7,6 +7,9 @@ import Figure from "~/components/Figure.astro";
 import Hint from "~/components/gitbook/Hint.astro";
 import Tabs from "~/components/gitbook/tabs/Tabs.astro";
 import Tab from "~/components/gitbook/tabs/Tab.astro";
+import image1 from "./_assets/paymentwall/paymentwall.tab.widget.png";
+import image2 from "./_assets/paymentwall/paymentwall.widget.jpg";
+import image3 from "./_assets/paymentwall/paymentwall.pingback.country_code.png";
 
 ### Widget (payment window) payment
 
@@ -92,20 +95,44 @@ Currently, PortOne supports widget codes `pw_1` and `t3_1`. To use the `pw_1` wi
 1. Go to [Paymentwall Console](https://api.paymentwall.com/developers/applications) → My Projects, select the relevant project → Widgets
 2. Select Version 1.2 and then save changes (SAVE CHANGES)
 
-import image1 from "./_assets/paymentwall/paymentwall.tab.widget.png";
-
 <Figure
   src={image1}
   caption="My Projects → Select relevant project → Widgets"
 />
 
-import image2 from "./_assets/paymentwall/paymentwall.widget.jpg";
-
 <Figure
   src={image2}
   caption="Select 1.2 from the top left Version → SAVE CHANGES"
 />
 
+### User country code
+
+You can know the user country code(alpha-2, e.g. US) as a pingback upon completion of a payment wall checkout. To get this, you need to add the [parameter provided by the paymentwall](https://docs.paymentwall.com/reference/pingback/custom-parameter#parameter-with-value-paymentwall-provides) as a pingback parameter.
+
+1. Go to [Paymentwall Console](https://api.paymentwall.com/developers/applications) → My Projects, select the relevant project → Settings
+2. Go to *Custom Pingback parameters* section
+3. Add *Name* as `country_code` and select *Value* as `COUNTRY_CODE`
+
+<Figure src={image3} caption="Add COUNTRY_CODE at Custom Pingback parameters" />
+
+You can check this result by adding the `extension=true` query parameter when querying payment as follows.
+
+```jsx
+GET http://api.iamport.kr/payments/{imp_uid}?extension=true
+```
+
+```json
+{
+  // ...
+  "vbank_name": null,
+  "vbank_num": null,
+  "extension": {
+      "country_code": "KR", // User Country Code
+      // ...
+  }
+}
+```
+
 ### API Payment
 
 <Tabs>

src/content/docs/ko/ready/2-pg/payment-gateway/paymentwall.mdx

@@ -14,6 +14,7 @@ import image3 from "./_assets/paymentwall/paymentwall-3.png";
 import image4 from "./_assets/paymentwall/paymentwall-4.png";
 import image5 from "./_assets/paymentwall/paymentwall.tab.widget.png";
 import image6 from "./_assets/paymentwall/paymentwall.widget.jpg";
+import image7 from "./_assets/paymentwall/paymentwall.pingback.country_code.png";
 
 ### 위젯(결제창)결제
 
@@ -103,6 +104,34 @@ import image6 from "./_assets/paymentwall/paymentwall.widget.jpg";
 
 <Figure src={image6} caption="좌측 상단 Version에서 1.2 선택 → SAVE CHANGES" />
 
+### 사용자의 국가 코드
+
+페이먼트월 결제 완료시 핑백으로 사용자의 국가 코드(alpha-2, e.g. US)를 수신할 수 있습니다. 이를 수신하기 위해서는 [페이먼트월이 제공하는 파라미터](https://docs.paymentwall.com/reference/pingback/custom-parameter#parameter-with-value-paymentwall-provides)를 핑백 파라미터로 추가해야 합니다.
+
+1. [페이먼트월 콘솔](https://api.paymentwall.com/developers/applications) → My Projects에서 해당 프로젝트 선택 → Settings
+2. *Custom Pingback parameters* 항목으로 이동합니다.
+3. Name에 `country_code` 추가 후 우측 Value에서 `COUNTRY_CODE`를 선택합니다.
+
+<Figure src={image7} caption="Custom Pingback parameters에 COUNTRY_CODE 추가" />
+
+이 결과는 다음과 같이 결제 건 조회시 `extension=true` 쿼리 파라미터 추가하여 확인할 수 있습니다.
+
+```jsx
+GET http://api.iamport.kr/payments/{포트원 번호}?extension=true
+```
+
+```json
+{
+  // 중략
+  "vbank_name": null,
+  "vbank_num": null,
+  "extension": {
+      "country_code": "KR", // 사용자의 국가 코드
+      // 중략
+  }
+}
+```
+
 ### API 결제
 
 <Tabs>